A KVM virtual machine (Kernel-based Virtual Machine) is a virtualized basic resource that is used in a Linux kernel, and can convert the Linux kernel into a hypervisor. The “kernel” refers to a system software component that provides functions such as a hardware abstract layer, a hard disk and file system control, multitasking, etc. The hypervisor, which is also known as virtual machine monitor (VMM), can be used for creating and executing a virtual machine on software, firmware or hardware. One or more virtual machines can be implemented by having a hypervisor. This type of computer is defined as a host machine, and a virtual machine implemented thereon is called a guest machine. The hypervisor can be manifested in a form of a guest operating system, and provides a virtual work platform that is responsible for managing operations of other guest operating systems. A plurality of operating systems run thereupon, and share hardware resources after virtualization.
A KVM virtual machine can run multiple virtual machines simultaneously without changing a Linux or Windows image, i.e., a virtual machine uses an image. KVM virtualization can run multiple virtual machines on a physical machine, and configure an individualized hardware environment (e.g., a network card, a magnetic disk, a graphics adapter, etc.) for each virtual machine. A KVM virtualization solution includes a downloadable core module which provides virtual functions of a bottom layer—a KVM module. The KVM module (i.e., kernel-based virtual module) includes kvm.ko and kvm-platform.ko (kvm-platform.ko includes kvm-intel.ko or kvm-AMD.ko, for example). The KVM module is a very important component in bottom layer virtualization technologies of cloud computing, such that the KVM virtualization solution is named after this module. The KVM module is the hypervisor in the entire virtualization solution.
In existing technologies, an upgrade of a KVM module requires that the KVM virtual machines be shut down. This leads to great cost in a public cloud environment, the environment not only suffering a large economic loss and needing to provide a higher amount of compensation for the time when the virtual machines are shut down, but also causing service interruptions to customers and even great losses to the customers.
However, a hot upgrade of an existing KVM module (i.e., an online upgrade of a KVM module without shutting down functions and services) does not exist in the art.